1. Technical Field
The present invention relates to an illumination device and a projector.
2. Related Art
As one of the light source devices used for projectors, there has been proposed a light source device for irradiating a phosphor layer with a laser beam as excitation light to generate fluorescence different in wavelength from the excitation light as described in JP-A-2011-113071.
In the light source device described above, a reflecting member is provided to a light transmissive member attached to a part of a rotary wheel to detect a rotation based on a periodic change of the reflected light due to the rotation. Thus, occurrence of a failure such as dropout caused in the rotary wheel is detected.
However, in the related art technology described above, since it is required to provide a complicated mechanism to the attachment section of the transmissive member, it takes cost, and a failure of a detection mechanism is apt to occur, which might cause a false detection. Further, since a detection section is disposed in an area overlapping the transmissive member, in the case of, for example, applying the technology to a transmissive diffusion wheel, there is also a problem that the detection method is limited in such a manner that the detection section is required not to hinder an effective use of the light used for display.